Spin injection-type Magnetic Random Access Memory (MRAM) provided with a magnetoresistive effect element (magnetoresistive element) having a ferromagnetic body as a memory element have been proposed. This MRAM, which operates by changing the magnetization direction of the magnetic layer using electric current injected into the magnetoresistive effect element, memorizes information by maintaining the electric resistance of the magnetoresistive effect element in one of two high resistance state/low resistance states.
In the spin injection-type MRAM, to reverse the magnetization direction of the magnetic layer, a sufficiently large inversion current, including a margin, flows to the magnetoresistive effect element. During switching of the magnetic state, an electric stress is imposed on the tunnel barrier layer which it is likely to cause dielectric breakdown. Furthermore, due to etching or other processing damages, a defect may be present in the peripheral part (the terminal part) of the tunnel barrier layer. Therefore, especially in the peripheral part of the tunnel barrier layer, the problem of dielectric breakdown or shorting due to the electric stress may occur.